1. Field of the Invention
The present device relates to a vortex flow meter in which two diaphragms cumulatively act for a signal output but differentially act against a noise to make the difference between noise outputs zero.
2. Prior Art
There are various kinds of vortex pressure detection systems. The Japanese Patent Application No. 36776/75 or the Japanese Utility Model Application No. 3725/79 disclosed a flow meter in which the pressure of vortices is transmited to a right and a left chambers divided from each other by a diaphragm to detect the difference in the pressure.
In a conventional flow meter of such kind, the sensitivity of a diaphragm needs to be made very high to detect the pressure of vortices in a range of very low flow rate. However, if the sensitivity is made very high, the diaphragm responds not only to the pressure of the vortices but also to an external force such as a vibratory force. This is a problem.